Respostas fisiológicas de Jatropha curcas L. à micorrização, adubação fosfatada e estresse hídrico

Abstract

This study aimed to evaluate the physiological responses of plants physic nut in association with mycorrhizal fungi under conditions of water stress and phosphorus levels. The experiment was conducted in a greenhouse in a 4x2x2 factorial scheme, with four levels of phosphorus: P0= P soil analysis; P1= 25 mg P/Kg soil; P2= 50 mg P/Kg soil; P3= 75 mg P/Kg soil, with or without inoculation with mycorrhizal fungi and presence or absence of water stress. Water stress caused a reduction in gas exchange, the maximum quantum efficiency of photosystem II (Fv/Fm) and in pigment plant physic nut, but did not affect the effective quantum efficiency. Phosphorus application inhibited photosynthesis in the presence of mycorrhizae and reduced pigment plants without mycorrhiza under irrigated. Inoculation of physic nut with mycorrhiza increased the productivity of dry mass at low levels of phosphorus. So could observe a negative interaction between P levels and presence of mycorrhizae in the development of physic nut.